对相位码雷达的移频干扰

相位码雷达信号具有辐射功率低,脉内有复杂的相位调制和处理增益高的特点,使电子对抗系统难以对它截获、分析和干扰。移频干扰是干扰相位编码雷达的一种方法。对移频干扰的计算机模拟表明,当干信比足够大时(幅度比约为3～5),移频干扰使巴克码的回波信号电平降低,在其两侧出现干扰峰。这些干扰峰随频移的增加呈有规律的移动。对于M序列码,移频干扰具有复盖干扰的效果。文中也研究了相位码子脉冲宽度、干扰与信号的相位差对干扰效果的影响。

Countermeasure to phase--coded radats by a shift--frequency jamming technique

The phase-coded radar signals feature a low radiation power, sophisticated intrapulse modulation and high processing gain, which makes it difficult for eletronic countermeasure (ECM) systems to intercept, analyze and jam radar signals. A shift-frequency jamming (SFJ) technique is proposed, which is easy to implement and has an excellent jamming effectiveness to the phase-coded radars. The simulation of SFJ has been accomplished. The results of simulation indicate that the jamming can reduce the processing gain of echo signals and create some jamming peaks. For the 13-bit Barker code, the peaks can be moved in accordance with the magnitude of the frequecy-shift of jamming signal, but for the 63-bit M sequence code, jamming can act as a cover jamming. The more the number of bits contained in the code, the higher the J/S ratio required. The range of frequency shift is limited, which it is usually lower than 1 MHz. If it is higher than 5 MHz, the jamming will lose its effect.